The lifetime prevalence, or the proportion of individuals expected to stutter at one time in their lives, is about 5%, and overall males are affected two to five times more often than females. Most stuttering begins in early childhood and according studies suggest 2.5% of children under the age of 5 stutter. The sex ratio appears to widen as children grow: among preschoolers, boys who stutter outnumber girls who stutter about two to one, or less. but widens to three to one at first grade and five to one at fifth grade, due to higher recovery rates in girls. Due to high (approximately 65–75%) rates of early recovery, the overall prevalence of stuttering is generally considered to be approximately 1%.